3/4" MDF, 5 layers per block, 2 blocks at 24"x24"
Mastercam, PartsWork3D (Generate Tool Paths)
ONSRUD CNC Machine (Milling)
At first I wanted to create a 2'x3' recycle bin using composites. But exploring the fabrication process it would have been messy, difficult to execute, and at such a scale pose severe toxic and safety hazards. It would have also been counter intuitive to promote ocean conservation and simultaneously be using toxic and unsustainable materials. After exploring several routes for fabrication to ensure I would not lose the form factor of the fish over re-layering (especially because the fish is already awkward-looking and it would not be desirable to lose anymore granularity or it would become completely unrecognizable) In rhino, it was straightforward since I took the same geometry I used from molding and casting week and scaled it to 24" x 96", the size of the bed on the ONSRUD CNC bot. The dimensions of the formech were 24"x24", which created a nice limitation for the dimensions of the project. I cut out a plane for the trash lid along with a flat base for the bottom fin. In hindsight, both cuts were unecessary.
The tool paths I first created in Partwork. But realizing that the ONSRUD does not take .SBP files, I went back to th archaic and nefarious mastercam. The tool paths were pretty straight forward: 1. Surface Rough using a 0.75" flat end mill 2. Surface finish scallop using a 0.5" end mill
I got a 4'x8' 3/4" MDF board, cut it into 8 tiles, and stacked it into two blocks necessary for the opposites of the fish. Using gorilla glue and clamps I stacked it together over night for drying. Rapidly evening the glue and ensuring a tight clamp is key to getting a seamless cut the day after.
Then it was ready to be cut. Each side took aproximately 2 hours to cut. The residue from the MDF was insane. It took me 30 minutes after each cut to vaccuum off all the saw dust
Being overly arrogant about my strength and trying to get my boards from N51 to building 7 without a trolley...humbled by the polar vortex, defeated, and waiting for a miracle to happen on Mass ave.
Thank God for friends
Thermoforming is a common method of processing plastic materials. My materials and machineries used include:
In order to create a vaccuum form, we had to drill holes in the MDF so the plastic would then stick to the MDF
According to McMaster-CARR, the maximum and minimum temperatures for PETG are between 140 to 100. We first tried setting it at 80, which did not melt the plastic enough. We then bumped it up to 100, and got a nice finish.
But it may have been a bit too hot, and the plastic ended up sticking to the rim. We ended up jigsawing the plastic off from the rim
Very happy with the results. I used a bansaw to trim off the edges, finished with a sander to create alignment on the flange, drilled holes and nailed the fish together using transparent 3/16" nails. In hind sight I could have used a CNC router to trim off the edges to get a cleaner finish.